There are many pipes such as gas pipelines, water and sewer mains typically laid and buried underground, so that municipal utility companies may supply their services, such as gas and water to or collect sewer from their customers via the underground pipelines. Generally, flow control valves are placed along the pipelines to control or actuate the supply to individual customers. And usually those control valves are located underground at the curb of an adjacent roadway.
For example, in a municipal water distribution system, water is supplied by a utility company to its customers via underground pipelines. A typical distribution system consists of two kinds of pipes: a main water conduit and service pipes. The main water conduit is also called a water main, which usually runs beneath the street and provides water to a whole subdivision. Service pipes are branched from the main, for supplying water to individual customers, such as buildings or houses. The flow of water between the main and the service pipe is controlled by an underground valve, usually termed a curb stop. The curb stop may be used as the isolation valve so as to shut off the water for repairs, nonpayment of water bills, flooded basements, and the like. The curb stop valve, typically located on the water receiving property close to the curb of the adjacent roadway and most typically beneath the front lawn or driveway, may be accessed from aboveground through a conduit known by names, such as valve can, valve box, curb box, or water box. The valve box extends from the valve up to the ground level, providing a conduit for insertion of a long-handled wrench or “key” to reach and turn the control knob of the valve. Some valve boxes may accommodate a control rod that is permanently attached to the knob of the valve. But, even this arrangement requires a special wrench or key to turn the valve on or off.
Sewer and water distribution systems are usually first to be put in place during the land development, and so are valve boxes. However, during subsequent construction activities, there are chances that different kinds of trades will move about the lots. It is not uncommon for heavy machinery to damage the installed valve boxes by running them over or inadvertently burying them, resulting in costly repairs or replacements or requiring searching for and excavating buried valve boxes, which is both time-consuming and tiresome. Further, there may be lateral force applied to the valve box due to displaced water saturated soil, rocks and/or roots. There also exists another problem in controlling the underground valve. When the valve is controlled by inserting a long-handled key through the valve box to reach a control rod attached permanently to the knob of the valve, the control rod may not necessarily stay at the centered position all the time. In many cases, it perhaps leans toward a side, consequently making it very difficult to reach and locate the top end of the control rod from above the ground level. Usually, it takes a long time to fish out the control rod, by making many attempts. There is still another problem in the prior art when the valve boxes are run over by unexpected huge or heavy machinery. Then the loads and pressures transmitted to the distal end of the valve box are so huge that the edge of the distal end will be pushed down on the pipelines underneath the box resulting in the pipelines being isolated from the location of the valve. Once this happens, it will be very difficult for it to be discovered and repaired.
Background art includes U.S. Pat. Nos. 6,802,337 and 5,738,140 which relate to valve boxes and associated valve control devices. U.S. Pat. No. 6,802,337 discloses a valve can extension comprising a tubular member having an extension riser portion at one end and an inwardly tapered portion at the other end. The inwardly tapered portion is adapted to be inserted into and frictionally engages a valve can bell housing, and the valve can extension and valve can bell housing assembly form a conduit from grade level to the bell portion, thereby making it available to complete the adjustment of the height of the valve box from above grade level with a minimum of excavation.
U.S. Pat. No. 5,738,140 relates to an adjustable-height extension stem and valve box assembly. The valve box is made up of a valve box base, a valve box lower section, a valve box upper section telescoping within the lower section and a valve box top. The extension stem comprises an upper section extending from the interior of the valve box top through a bottom opening and a lower section extending downwardly from the upper section, with the two sections being made from square hollow metal tubing such that the upper section telescopes within the lower section. However, neither of these patents addresses the above-mentioned problems.
Therefore, one object of the present invention is to provide a valve box which is damage-resistant and bury-resistant, capable of providing clear indication of the presence and position of the valve and allowing access to the valve with minimal interruption during phases of construction and service.
Another object of the present invention is to provide a valve control device used in a valve box, which is capable of locating an uncentered control rod easily and keeping the control rod in a steady centered position.
Another object of the present invention is to provide a valve box which is capable of absorbing heavy pressure from above, in a manner which prevents the pipeline underneath from being pushed down, to maximize resiliency and to minimize obstructions to access, so as to resist and to deflect lateral pressure, as described above, and pressure points on the valve box.
It is yet another object of the present invention to provide a valve box and valve control device assembly, which is kept in place during all phases of construction with minimal disruption, renders it easy to access the underground valve and provides a clear indication of the presence and position of the valve during all phases of construction with minimal disruption and servicing of the valve.